package Network;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class HomeworkTcpEchoServer1 {
    private ServerSocket socket = null;

    public HomeworkTcpEchoServer1(int port) throws IOException {
        socket = new ServerSocket(port);
    }

    public void start() throws IOException {
        System.out.println("服务器启动.");
        while(true){
            Socket clientSocket = socket.accept();

            processConnection(clientSocket);
        }
    }

    // 处理一个客户端的连接
    private void processConnection(Socket clientSocket) {
        System.out.printf("[%s %d] 客户端上线!\n",clientSocket.getInetAddress(),clientSocket.getPort());

        try(InputStream inputStream = clientSocket.getInputStream();
            OutputStream outputStream = clientSocket.getOutputStream()){
            Scanner scanner = new Scanner(inputStream);
            PrintWriter writer = new PrintWriter(outputStream);

            while(true) {
                // 1.读取请求并解析
                if(!scanner.hasNext()){
                    System.out.printf("[%s %d] 客户端下线\n",clientSocket.getInetAddress(),clientSocket.getPort());
                    break;
                }

                String request = scanner.next();

                //2. 根据请求计算响应
                String  response = process(request);

                // 3. 返回相应到客户端
                writer.println(response);
                writer.flush();

                System.out.printf("[%s %d] req : %s,resp : %s\n",clientSocket.getInetAddress(),clientSocket.getPort(),
                        request,response);


            }

        }catch (IOException e) {
            throw new RuntimeException(e);
        }

        }

    private String process(String request) {
        return request;
    }

    public static void main(String[] args) throws IOException {
        HomeworkTcpEchoServer1 server1 = new HomeworkTcpEchoServer1(9090);
        server1.start();
    }
}
